Copyright (c) 1998 Alan Barclay. All rights reserved.
This program is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.
Please send questions or bug reports to me rather than posting them to
a newsgroup since I may miss them there.
INSTALLATION
To install, just type
perl Makefile.PL
make
make test
make install
TESTS
By default, the dbi tests are not performed. You need to edit the
t/dbi.t file and set up the correct database & driver.
Here is the documentation for the module, directly from the pod
NAME
Set::NestedGroups - grouped data eg ACL's, city/state/country etc
SYNOPSIS
use Set::NestedGroups;
$nested = new Set::NestedGroups;
$nested->add('user','group');
$nested->add('group','parentgroup');
do_something() if($nested->member('user','parentgroup'));
DESCRIPTION
Set::NestedGroups gives an implementation of nested groups, access
control lists (ACLs) would be one example of nested groups.
For example, if Joe is a Manager, and Managers have access to payroll,
you can create an ACL which implements these rules, then ask the ACL if
Joe has access to payroll.
Another example, you may wish to track which city, state and country
people are in, by adding people to cities, cities to states, and states
to countries.
CONSTRUTORS
new()
creates a new Set::NestedGroups object.
new( fh )
creates a new Set::NestedGroups object, the object will be
initialized using data read from this handle. For details on the
format, see the save() method
new( $sth )
creates a new Set::NestedGroups object, the object will be
initialized using data read using this this DBI statement handle.
For details on the format, see the save() method
METHODS
add ( $member, $group)
adds a member to a group. The group will be created if it doesn't
already exist.
remove ( $member, $group )
removes a member from a group. If this was the last member in this
group, then the group will be deleted. If the member was only in
this group, then they will be deleted.
save(FILEHANDLE)
Outputs the object to the given filehandle, which must be already
open in write mode.
The format is compatable with the format used by CGI, and can be
used with new to initialize a new object;
Returns true if successfully wrote the data, or false if something
went wrong (usually that meant that the handle wasn't already open
in write mode).
save($sth)
Saves the object to a DBI database. This can be used with new to
initialize a new object. The $sth should be expecting 2 values, in
this fashion:
$sth = $dbh->prepare('insert into acl values (?,?)')
$acl->save($dbh);
$sth->finish();
$sth = $dbh->prepare('select * from acl');
$newacl=new ACL($sth);
Returns true if successfully wrote the data, or false if something
went wrong.
member ( $member, $group )
Returns true if $member is a member of $group.
member ( $member )
returns true if $member exists in any group.
group ( $group )
returns true if $group exists
groups ( $member, %options )
Returns the groups that $member belongs to. Options are explained
below.
members ( $group , %options )
Returns the members of $group. Keep on reading for the options
list(%options)
Returns a Set::NestedGroups::Member object that will output an list
of the members & groups. This could be considered a calling of
groups() on each member, except this is more efficent.
The object can be used as follows.
$list=$nested->list();
for(my $i=0;$irows();$i++){
my ($member,$group)=$list->next();
print "$member=$group\n";
}
options
By default, the above methods give every valid combination. However
you might not always want that. Therefore there are options which
can prevent return of certain values.
All of these examples presume that 'joe' is a member of 'managers',
and 'managers' is a member of payroll, and that you are using only
one of these options. You can use all 3, but that gets complicated
to explain.
-norecurse=>1
No Recursion is performed, method would ignore payroll, and return
only managers.
-nomiddles=>1
Doesn't returns groups 'in the middle', method would ignore mangers,
and return only payroll.
-nogroups=>1
Doesn't return members that are groups. This only applies to the
list() method, in which case it acts like nomiddles, except on the
member instead of the group. list would ignore managers and return
joe => managers , joe => payroll.
This sounds a lot more confusing than it actually is, once you try it
once or twice you'll get the idea.
AUTHOR
Alan R. Barclay, gorilla@elaine.drink.com
SEE ALSO
perl(1), CGI, DBI.